The present invention relates to an apparatus and method for use in channelizing telephone transmission equipment, and in particular, to providing channel redundancy to replace defective equipment remotely thereby providing immediate restoral of service and delay in repair dispatch.
Subscriber loop pair gain systems are well known in the prior art and the testing of such systems is disclosed for example in U.S. Pat. No. 4,270,030 issued to Brolin et al. This patent discloses a testing system for telephone subscribing loops which are in part derived by multiplex facilities and systems known as pair gain systems. In this testing arrangement, the local drop wires from a remote terminal of the pair gain system to the subscriber are separated from the carrier system itself and are tested by connecting them to a separate metallic pair extending from a central office to the remote terminal location. Simultaneously, the carrier derived portion of the subscriber loop is connected to automatic testing apparatus which sequences through a plurality of automatic tests for not only transmission characteristics of the carrier derived channel, but also for testing the ability of the derived channel to transmit information such as ringing, coin control, on/off hook states and party identification information. The remote terminal of the pair gain channel is selectively terminated by a reflective or absorbitive termination to assist in this testing procedure. The testing system is designed so as to make carrier derived channels appear to the central office testing personnel as if they were identical to metallic loops.
Rockwell International provides products to implement digital loop carrier systems which include appropriate software for affecting such tests as described above. In a typical digital loop carrier system, a channel bank at a remote terminal or at the central office will contain a plurality of channel units. In the present technology, these channel units have no redundancy or backup units for automatic replacement. In channelizing equipment associated with such telephone equipment, individual channel units or circuit modules associated with specific channels, make up the majority of equipment prone to failure. Failures of this type must be repaired as soon as possible in order to restore telephone service to a customer, usually within a matter of hours. This equipment may be located in areas that are not easily accessible on a 24-hour basis, and dispatching of repair personnel during "non business" hours may be extremely costly. Thus, there is a need in the prior art to provide a method and apparatus to replace the defective equipment remotely in order to provide immediate restoral of the schedules permit.
The present invention provides a solution to this drawback in the prior art.